I second that. The iphone is OK, but inconvenient to change volume etc, and loses signal frequently. The ipad app is fab. Really clear to use and read.Then you try the CR200 - not cheap but it is a quality product, which the Sonos setup deserves.I was unsure why anyone would bother with a CR200 when there is free software for the iPod/iPhone/iPad and now Android. When you actually use the CR200 the answer is more obvious, because as good as the apps are, the dedicated controller is really very good. I have a CR100, CR200 and the apps on an iPhone. I use all 3 at various times but the CR200 is my personal favourite. Is it worth the money? That's down to the individual I guess, you certainly don't need one, but you probably want one.
One other advantage of the controller over the apps which I found out today. The controller works when its in range of any other sonos device. My phone only works when its in range of the router. So if uve got a big house or garden you need a decent strength WiFi signal to use the app everywhere.